This application makes reference to and claims all benefits accruing under 35 U.S.C. Section 119 from an application entitled xe2x80x9cPlanar Lightwave Circuit Type Optical Amplifierxe2x80x9d filed in the Korean Industrial Property Office on Oct. 12, 2001 and assigned Serial No. 2001-62880, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to an optical amplifier. More particularly, the present invention relates to a Planar Lightwave Circuit (PLC) type optical amplifier.
2. Description of the Related Art
Optical signal amplification using an Erbium-Doped Fiber Amplifier (EDFA) in an optical communication system provides dramatic cost reductions associated with the implementation of the optical communication system. In addition, the use of EDFA also contributes substantially to the increase in optical communication efficiency. In the future, optical amplification technology is expected to be subsequently developed toward the application of EDFAs to PLCs, known as erbium-doped waveguide amplifiers (EDWAs). Studies have been conducted actively in order to put the EDWAs to practical use because they enable the integration of complex optical devices.
However, such a PLC type optical amplifier doped with rare earth metal ions, such as erbium or transition metal ions, has a low amplification rate per unit length. Therefore, the PLC type optical amplifier has limitations in achieving both a desired amplification rate and high integration.
It is, therefore, an aspect of the present invention to provide a PLC type optical amplifier that ensures a high amplification rate and high integration.
The above and other aspects of the present invention are achieved by providing a PLC type optical amplifier comprising an amplification layer formed of a light amplifying material on a semiconductor substrate at a side of a core layer, and spaced from the core layer. The amplification layer forms an annular light path. Thus, optical signals are coupled between the core layer and the amplification layer.